This invention relates to a circuit arrangement for controlling an alternating current through a load, a terminal of which is connected to a first power supply terminal, said circuit arrangement being connected during operation between the other load terminal and the other power supply terminal and comprising a series circuit of a resistor section and a capacitor section connected between the other load terminal and the other power supply terminal, and a controlled rectifier connected between the other load terminal and the other power supply terminal, the control current for the controlled rectifier being taken via a diac from the junction point between the resistor section and the capacitor section.
A circuit arrangement of this type is known, for example, from Netherlands Patent Application 7003842. If such relatively simple circuit arrangements are used, for example, for controlling a motor or the like, electronic components will generally be used which have a relatively large tolerance in their electrical specification. The result is that at least a control component, for example, a potentiometer is required to control the minimum phase angle of the phase control of the controlled rectifier to the desired value. This control component must be adjusted to the correct value in a control procedure and which is considered to be a serious drawback, particularly in the case of mass production of large numbers of such circuit arrangements.